"What is concerning, however, is that the system that was potentially
tested, according to reports in South Korean media, was one of North
Korea’s more advanced missile systems, a 300-mm [12 inch] artillery rocket
launching platform, commonly referred to as the KN-09"

"The
system, per the Center for Strategic and International Studies, has a
range of 190km [118 miles], carrying a total of eight rockets in two pods of four
launchers. These deadly weapons sit on a mobile truck, making them
mobile and harder to destroy in a conflict."